In the field of automotive industry, especially in the area concerned with the development of electric vehicles, different devices, methods and systems for recharging the battery bank of electric vehicles have been developed. There has also been an investigation into more efficient energy consumption in order to provide enhanced autonomy to the vehicle. However, it is beyond doubt that every electric vehicle requires a time to recharge the energy of the battery bank, the main disadvantage being that said time is much longer compared to the time to recharge fuel in an internal combustion car.
The big automotive brands have tried to reduce this time by opting for systems which allow recharging batteries in four hours instead of eight. Consequently, the cost of recharging equipment plus the cost of batteries, which must comply with the technical specifications required by the recharging device, must be added to the value of an electric vehicle.
If an electric vehicle is plugged directly to a 110 VAC electrical outlet, the on-board chargers are fed alternating current (AC), convert it to direct current (DC) and regulate the power that is being supplied to the battery bank. However, in case a fast charging or supercharging is used, the on-board charger and the conversion from AC to DC takes place outside the vehicle. A challenge for fast charging is that when a battery is supplied with energy very quickly, it experiences wear, which shortens its life. Therefore, in order to avoid damaging the battery, the external charger has to communicate adequately with the electronic components tracking the battery condition, including its voltage and temperature, to adjust the fast charging rates accordingly. To achieve this manner of charging, the charger has to be adequately designed to work in perfect synchrony with the measured parameters of the battery condition.
In order to achieve charging times of less than twenty minutes, it is necessary not only to further improve the charging system, but also to improve the interface with the electrical grid, due to the fact that power points that support loads of 120 kilowatts are required. Therefore, extracting large amounts of power from the grid implies costs associated with power demand on the electric power company, which further increases the price of the charging system.
In this regard, the Chinese patent application CN104333108 describes an emergency electrical charging system for an electric vehicle. The system comprises a diesel generator, an integrated AC-DC fast-charging device, a storage battery mounted in the vehicle, an electrical supply and an electric vehicle. The integrated fast-slow charging device comprises an AC-DC rectifier and voltage regulator module, an inverter module and a secondary voltage regulator module. The diesel generator and the power supply are connected to the rectifier and regulator module. The storage battery output port is mounted on the vehicle. The rectifier and voltage regulator module are connected to the end of the input port of the storage battery mounted in the vehicle. The output end of the rectifier and voltage regulator module is connected to the input end of the inverter module. The output end of the storage battery mounted in the vehicle is connected to the respective input ports of the inverter module and the secondary voltage regulator module. The inverter module and the secondary voltage regulator module are connected to the electric vehicle, when the electric vehicle is inactive, the power supply is connected to fully charge the storage battery mounted in the vehicle, and when the electric vehicle is in a charging state, the diesel engine alone charges the battery mounted in the vehicle. However, said emergency electrical charging system has the disadvantage of requiring another energy generating source that is powered by diesel fuel.
Japanese patent application JP2014204549 describes a power supply system accompanied by a method for charging an auxiliary battery of the main battery by means of a charge control device during the time in which the electric vehicle is parked or inactive. In this invention, the system includes: a solar panel, a solar charger and a section for detecting solar electrical charging energy. The solar panel is attached to an exterior panel of a vehicle, for example a roof panel. The solar charger charges the auxiliary battery with the electrical power generated by the solar panel. The section for detecting solar electrical charging energy detects the amount of charge in the auxiliary battery, according to the amount of energy of the auxiliary battery charged by the solar charger, where an integration electronic control unit (ECU) controls and adjusts the time to complete charging in order to start charging. However, the invention described would be insufficient to recharge a battery bank via solar panel; in order to do it, a solar panel system that supplies the amount of energy required to recharge the battery bank of the electric vehicle is necessary.
Japanese patent application JP2014183713 discloses a battery recharging device for charging an accessory battery, with adequate electrical power during a parking period. An accessory battery of the charging system performs a first charging in order to charge an accessory battery at each predetermined time, for example, while the electric power source of the vehicle is off, and a second charging for supplying electrical power to the accessory battery. Meanwhile, a replacement device or communication device of the vehicle has carried out the communication while the power source is off. The method for increasing the electrical power supply is exemplified by means of a method for increasing the charging time or a method for increasing the output voltage value of a DC-DC converter. Therefore, said invention has the disadvantage of being suitable only for recharging a single accessory battery at times when the vehicle is parked, which lacks the capacity to charge the battery bank of an electric vehicle.
The US patent application US2014203077 describes a charging system for the battery for an electric vehicle, wherein an RFID tag, an RFID receiver, an electrical charger and a controller operate to charge the battery of an electric vehicle according to a user profile and a charging profile in response to a signal from the RFID tag received by the RFID reader. In an interconnected system, multiple charging stations are connected to the power grid and communicate with a central controller through communication links. A grid converter can be provided to allow recharging the energy of the electric vehicle from the electrical grid in response to a command from the central controller. Therefore, said invention requires an additional investment for the charging stations infrastructure as well as relevant adjustments to the electrical grid in order to supply the charging stations, which represents an overall disadvantage for the usage of electric vehicles.
Japanese patent application JP2014108031 describes a charge/discharge control device, which controls charge/discharge of a power storage device provided with a first power storage unit having a relatively high energy density and a second power storage unit having a relatively low energy density, includes: a determination unit which detects charging/discharging power values in the first power storage unit and the second power storage unit, a power consumption value consumed by a load, and a charging power value supplied from a generator and outputs a charge/discharge control signal based on these detected values; a first charging/discharging unit for charging/discharging the first power storage unit on the basis of the charge/discharge control signal; and a second charging/discharging unit for charging/discharging the second power storage unit on the basis of the charge/discharge control signal. Power to be charged/discharged to/from the first power storage unit and the second power storage unit is determined in accordance with power supplied from the generator to the power storage device and power supplied from the power storage device to the load. The above represents additional costs associated with using high energy density batteries, as well as specific electric/electronic devices for recharging the same.
The inventions mentioned above, applied to the automotive industry in the field of electric vehicles, in particular require the users to invest an additional capital to equip their electric vehicle with a system or equipment for fast recharging of the vehicle battery bank that prevents long standby times when recharging the battery bank.
Therefore, electric vehicles are not fully acceptable to users mainly because of the high cost of such vehicles, the autonomy and the long time required to recharge the battery bank if there is no adequate electrical equipment for fast charging of the battery bank. Vehicle users are accustomed to having their vehicles available for use almost all the time, and there are even economic sectors in which the availability of the vehicle is a paramount need.
However, in order to avoid such long battery bank recharging times, not only is a special equipment needed for quick recharging of the battery bank, it is also necessary for the electrical infrastructure to support the high amounts of current required for its operation. Despite the fact that electrical power is available everywhere, in order to achieve fast recharges of the battery bank, capacity of the electrical grid and adequate electrical equipment to achieve said purpose are necessary.
The present invention provides a solution to this problem, especially applied to electric vehicles used in the distribution of commercial products, where the standby time while recharging the battery bank is an undesirable factor and the option to quickly recharge the batteries is not feasible due to the vehicle batteries being quickly damaged or the economic costs involved.
Given the prior art, there is a need to provide a system that allows easy replacement or exchange of the entire low-charge-level battery bank by another battery bank having an optimum charge level for the operation of the electric vehicle, without the need to wait for the battery bank of the vehicle to be fully charged in order to use the vehicle again.
The present invention does not require a special infrastructure for the fast recharging of batteries nor the investment that making the corresponding adjustments to the electric network, installing the recharging stations, periodic maintenance, and energy consumption rates entail.
Those skilled in the art know the need for a system that allows the battery bank of an electric vehicle to be mounted and removed in the shortest amount of time possible and replaced with another previously charged battery bank and for a solution to the eight-hour recharging times of the vehicle battery bank, considering that in the economic sector where the vehicle is used, the time factor is paramount for the company or business.
The present invention allows an efficient programming in the distribution routes that the electric vehicle(s) must comply with, considering the performance of the battery bank charge and the autonomy of the electric vehicle plus the estimated time for the replacement of the battery bank. Therefore, the vehicle user or the company does not require special equipment or expensive infrastructure to optimize the recharging time of the battery bank.